Mining Nontraditional Water Sources for a Distributed Hydrogen Economy

Securing decarbonized economies for energy and commodities will requireabundant and widely available green H2. Ubiquitous wastewaters and nontraditional watersources could potentially feed water electrolyzers to produce this green hydrogen withoutcompeting with drinking water sources. Herein, we show that the energy and costs of treatingnontraditional water sources such as municipal wastewater, industrial and resource extractionwastewater, and seawater are negligible with respect to those for water electrolysis. We alsoillustrate that the potential hydrogen energy that could be mined from these sources is vast.Based on these findings, we evaluate the implications of small-scale, distributed waterelectrolysis using disperse nontraditional water sources. Techno-economic analysis and lifecycle analysis reveal that the significant contribution of H2 transportation to costs and CO2emissions results in an optimal levelized cost of hydrogen at small- to moderate-scale waterelectrolyzer size. The implications of utilizing nontraditional water sources and decentralizedor stranded renewable energy for distributed water electrolysis are highlighted for severalhydrogen energy storage and chemical feedstock applications. Finally, we discuss challengesand opportunities for mining H2 from nontraditional water sources to achieve resilient and sustainable economies for water andenergy.